1. Field of the Invention
The present invention relates to the field of power generation using thermoelectric devices.
2. Description of the Related Art
Although it has long been understood that thermoelectric devices can be used to generate power, thermoelectric power generation has been little utilized because the efficiency of present generator design and the power density of such generators are too low.
Historically, solid-state electrical power generating systems are constructed from TE Modules or stand-alone TE elements placed between a source of heat and a heat sink. The parts are designed with no moving parts in the power generator. Generally, systems that use hot and cold working fluids as the hot and cold sources employ fans or pumps to transport the fluids to the assembly.
In other applications, pressurized air and fuel are combusted within the generator. Still in other applications, such as automotive exhaust waste power converters, heat is transported to the generator by the exhaust system. In these devices, the waste heat is removed either by external fans supplying coolant or by free convection through finned radiators.
In applications such as generators that employ nuclear isotopes as the heat source, individual TE elements are configured to produce electrical power. Each TE element is attached to an isotope heat source on the hot side, and to a waste heat radiator on the cold side. No parts move during operation.
Texts that describe solid-state TE power generation are either written contemplating spacecraft usage (Angrist, Stanley W., Direct Energy Conversion, Third Edition, Allyn and Bacon, Inc. (Boston, 1976). Chapter 4, pp. 140-165) have been concerned with terrestrial applications for which reliability rather than efficiency has been the primary goal or have used formulaic models (Ikoma, K. et al., “Thermoelectric Module and Generator for Gasoline Engine Vehicles,” 17th International Conference on Thermoelectrics, Nagoya, Japan, (1998), pp. 464-467) that do not necessarily optimize system performances for today's applications. The need exists to develop and use TE power generation cycles for current and future applications including waste heat recovery from vehicle exhaust and engine coolant, from industrial waste process heat, and from co-generation systems that benefit from electrical power production.